/* ===================

AX2E (AXESCON XACML 2.0 Engine) is the Java authorization engine, which implements OASIS XACML 2.0 standard.
Copyright (C) 2007 AXESCON LLC

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA


Contact: AXESCON LLC - info{at}axescon.com

 =================== */
package axescon.xacml.engine.fn;

import axescon.xacml.api.*;
import axescon.xacml.model.policy.AttributeValue;

/**
 * @author Date: Sep 28, 2005
 *         Responsibilities: implements Bag functions from
 *         see axescon.xacml 2.0 spec ch. A.3.10 Bag functions
 */
public class FnBagOneAndOnly extends AbstractFn implements Fn {
    public int getArgTypeListLength() {
        return 1;
    }

    public Liquid exec(Liquid[] args) throws ExpressionEvalIndeterminateException {
        return new Liquid(execOnBag1(args[0].getBagUnsafe()));
    }

    private AttributeValue execOnBag1(AttributeValue[] arg0) throws ExpressionEvalIndeterminateException {
        if (arg0==null || arg0.length != 1)
            throw new FunctionEvalIndeterminateException("FnBagOneAndOnly.execOnBag1(...) has empty arg list.",
                    XacmlException.ERR_CODE_PROCESSING_FN_EMPTY_ARG).setFnUrn(getFnUrn());
        return arg0[0];
    }


    public FnBagOneAndOnly() {
    }

    


}
